The 91 Freeway between Fullerton and Corona is one of the most congested stretches of highway in California — an often frustrating bog of idling engines, squeaking brakes and commuter angst.
The rush hour traffic results from an abundance of jobs in Orange County and more affordable housing in the Inland Empire.
But for almost a decade, Caltrans and local transportation agencies were prevented from improving the heavily congested portal.
The problem: A 10-mile, four-lane tollway in the median that was owned and operated by a private company. Under its 35-year agreement with Caltrans, lane additions on the 91 were prohibited if they threatened to draw motorists away from the tollway. The company even had veto power over projects.
After years of controversy, the Orange County Transportation Authority finally bought the 91 Express Lanes for $207 million in 2003 and scrapped the noncompetition agreement, clearing the way for a long-range effort to overhaul the highway.
As the sale closed, OCTA board Chairman Tim Keenan declared, "The real work begins."
Now in the 11th year of a 30-year plan, upward of $2 billion has been either spent or earmarked for lane additions, rebuilt interchanges, new ramps and the expansion of public transit on both sides of the Riverside-Orange county line.
"It would have been so much worse had we not been able to do the things we've done," said Darrell Johnson, the OCTA's chief executive. "We could have been on our way to a complete failure in the corridor, but we've managed to turn that around."
Last year, the average number of trips motorists made per day ranged from 209,000 to 338,000 depending on the section of freeway, according to Caltrans. In 2000, the range was 220,000 to 298,000 trips.
If projections are correct, the number of trips could exceed 400,000 a day by 2035 on the Riverside portion of the 91. In Orange County, average daily traffic could jump by 90,000 trips, more than 30%.
"It's been frustrating," said Eric Carpenter of Eastvale in Riverside County, who has commuted on the 91 for more than a decade to jobs in Santa Ana. "We've always told people our house was a beautiful place to be once you got there. Getting up every day to make that commute has been real difficult."
Carpenter now uses the 91 Express Lanes for free because he carpools with his wife and daughter. The toll lanes otherwise offer motorists freeway speeds for a price that fluctuates with the level of congestion.
"That is a godsend for us," Carpenter said, although it can still be slow going in Corona where highway construction is underway. "I look at the regular lanes and count our blessings."
The first expansion of the 91 was a $6.7-million lane addition that opened in 2004 in Orange County. The westbound lane, which runs for a half-mile from the Riverside-Orange county line to the Foothill Eastern toll road, eliminated one of the worst choke points on the highway.
After the improvement, officials said the average speed doubled from 12 mph to 28.5 mph through an 11.7-mile section of freeway. Some motorists reported 15- to 20-minute reductions in their commutes.
Since then, there have been re-stripings to add lanes, right-of-way acquisitions, planning and environmental reviews for proposed projects.
The OCTA, working with Caltrans and the Riverside County Transportation Commission, has committed more than $360 million for 23 miles of lane additions along various parts of the 91 between Interstate 5 and the Riverside County line. About half the lanes are finished. The others will be done in 2016 and 2018.
The OCTA, Caltrans and the Transportation Corridor Agencies in Irvine also are planning a $180-million flyover to better connect the 91 and 241 toll road through northeastern Orange County. Officials say the project is designed to end the long back-ups of traffic on the eastbound 91 at the tollway ramp.
In addition, the Riverside Transit Agency and the OCTA have added express bus routes along the 91. The Metrolink commuter railroad, which serves six Southern California counties, also added service to its Inland Empire-Orange County line.
There are indications that some of the improvements are working.
Caltrans officials said the completion of a widening project on the 91 between the 55 Freeway and the 241 toll road helped to reduce the delay experienced by all motorists from 5,169,147 hours a year in 2010 to 3,657,120 in 2011, or 29%.
In 2012, preliminary Caltrans figures show the amount of annual delay dropped an additional 12%. The latest available data from early 2014 shows, however, that the amount of time wasted in traffic per year because of congestion is on the rise.
In the least, transportation officials say, the improvements have kept up with the growth in traffic, and commute times have not increased.
Some longtime commuters say that they haven't noticed much change in their travel times and that the benefits of completed highway projects were only temporary.
"There is heavier traffic today," said Michele Moran, a teacher who has commuted for 13 years from Riverside to Fullerton, a 30-mile trip that can take at least an hour. "I don't see any difference in my commute times."
After a lane addition several years ago, Carpenter estimated that he could shave 10 to 15 minutes off his commute.
"I definitely saw a difference," he said. "But once there are new lanes, they fill up."
He said, however, he expects that the ongoing construction to improve the 91 through Corona will relieve some of the congestion after it is finished.
The $1.4-billion project, which is between the Riverside-Orange county line and Interstate 15, will extend the tolled Express Lanes into Riverside County, add a lane in each direction of the 91, improve six interchanges and rebuild the interchange of the 15 and 91. The work is scheduled to be finished in early 2017.
But Corona City Councilwoman Karen Spiegel, a member of the Riverside County Transportation Commission, says more must be done to reduce traffic congestion on the main link between the counties.
"The expansion of the 91 is not the only answer," Spiegel said. "We still need to get companies to move jobs to the Inland Empire, and we need to look for an alternative corridor. If we have a single traffic accident on the 91, there is a domino effect throughout Riverside County."
Follow on Twitter @LADeadline16 for transportation and aviation news.